Fixed installations of nozzle devices of this kind are known as component parts of aircraft fire extinguishing systems for cargo holds. The nozzle devices are connected via a pipeline system to storage tanks containing fire extinguishing medium and are used, on activation of the fire extinguishing system, for purposeful discharge (spraying, sprinkling etc.) of the fire extinguishing medium into a cargo hold.
Depending on their size, cargo holds have one or more of these nozzle devices, in order to achieve optimum distribution of the fire extinguishing medium and therefore optimum fire fighting. In the present text the term “nozzle device” is to be understood in its broad sense. It comprises at least one discharge nozzle and optionally further parts, for example a nozzle holder, with which the discharge nozzle is secured in or on a cargo hold wall. Such nozzle holders can be specially shaped, to support intentional, purposeful discharge of the fire extinguishing medium leaving the discharge nozzle and to protect the discharge nozzle against damage during loading operations.
The known nozzle devices are typically made of stainless steel and have corrosion protection applied thereon, which is formed in a great variety of ways, for example by a zinc-nickel coating or with an adhesive protective film. In case of fire, the nozzle devices must maintain their function and integrity under the action of specified temperatures, for example 900-1000° C., for a specified minimum time of action, for example 5 min. This must be demonstrated in corresponding tests within the scope of component approval. Further material requirements are given in the approval or construction specifications.
In the course of the constant efforts in aircraft construction to achieve weight reduction, the problem to be solved by the invention is to provide a nozzle device that fulfills the approval criteria with respect to fire protection and is lighter than the known nozzle devices.